My Vision Test

MyVisionTest News Archive

Oct 20, 2009

Spontaneous drusen regression in AMDMacular soft drusen may fade or disappear without detectable signs of local dysfunction, according to a new study.

Drusen are yellow deposits of waste products that accumulate on Bruch's membrane under the retinal pigment epithelium. An increase in the size or number of drusen raises a person's risk of developing either advanced dry AMD or wet AMD. There are several types of drusen, including hard and soft types. Hard drusen are round shape with distinct, well defined borders and are usually small. Soft drusen are pale yellow with ill-defined borders, vary in size and shape and tend to be larger than the hard form. Soft drusen are usually associated with a greater likelihood of progression of macular degeneration.

In the current study patients were selected from a large ongoing collection of clinical data at Moorfields Eye Hospital. Phenotyping based on standard colour fundus images was p[erformed by certified masked graders. Fundus autofluorescence (FAF) was recorded using a Heidelberg Retina Angiograph 2. Where drusen regression was confirmed by independent grading, the patient was invited for photopic and scotopic fine matrix mapping (FMM). Phenotype and functional data were analysed for correlations between fundus appearance, autofluorescence and retinal sensitivity.

Fundus and FAF images of 960 patients were screened, soft drusen regression was detected in 34 cases (3.5%), and 14 patients agreed to participate in the study, ranging in age from 52 to 84 years (median 72). The mean follow-up period was 5.9 years (range 2.8–14.4 years). FMM showed generalised threshold elevation relative to normal controls both under photopic and scotopic conditions. Scotopic sensitivity loss exceeded photopic loss in all cases. Sensitivity loss over areas with drusen or regressed drusen did not differ significantly from that over non-drusen areas.

The investigators conclude that macular soft drusen may fade or disappear without detectable ophthalmoscopic, FAF or psychophysical signs of local dysfunction. The prognosis for cases with true regression of drusen compared with those without needs to be considered in future studies on AMD.